


Just A Little Magic

by TellTaleKael



Series: Undertale Kinktober 2019 [4]
Category: Undertale (Video Game)
Genre: Alternate Universe - Fellswap, Alternate Universe - Underfell, Lactation, Lactation Kink, M/M, Milking, PWP, Porn Without Plot, Pregnancy, Slim Is A Nasty Boy, Smut, Undertale Kinktober 2019, With Hints Of Pregnancy Kink, milk drinking
Language: English
Status: Completed
Published: 2019-10-05
Updated: 2019-10-05
Packaged: 2020-12-03 23:39:47
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 967
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20900792
Author URL: https://archiveofourown.org/users/TellTaleKael/pseuds/TellTaleKael
Summary: Undertale Kinktober 2019Day 4: Lactation | Pairing: Slim/RedWith a babybones on the way, Red’s had been feeling more than a little sore. Thankfully, his mate Slim was willing to lend a hand.





	Just A Little Magic

Red stared at the ceiling and groaned loudly into the empty apartment. He hadn’t moved from the couch in a couple of hours, lying there in just his loose shorts. He hadn’t even bothered to get up to turn the lights on when the living room began to grow dark with the approaching night, merely letting the glow of his summoned ecto flesh light the ceiling he stared at.

Finally, the unmistakeable sound of the front door opening brought him out of his trance. He shuffled around to sit up, groaning when his heavy, aching breasts bounced with the movement. Slim came around the corner, eyelights landing on Red and a smile stretching across his face.

“Well, that’s a helluva sight to come home too,” he purred. Red rolled his eyes, kicking his legs off of the couch and resting a hand on his swollen stomach.

“yeah, yeah, we all know yer a perv. get that skinny ass over here already,” Red grumbled. Slim obliged, crossing the living room in long strides and collapsing on the couch. He pulled Red into his lap, facing him. Slender hands rested on Red’s stomach, over the tiny, fluttering soul within, and Slim clacked a kiss against his cheekbone.

“How’re my two best guys?” he asked, gently rubbing circles onto red ecto flesh.

“oh he’s great. sucking up all my energy, so he should be nice and strong.” Red shifted slightly, making himself comfortable on Slim’s boney lap. “i feel like i’ve been run over. twice.”

“Poor baby,” Slim cooed. Red swatted at him.

“shuddup, you asked!”

“Mm, why don’t you tell me where you hurt, and I’ll see what I can do?”

Red squinted his sockets, but he didn’t see any hint of a trick on his mate’s face, so he murmured, “well, my back ain’t exactly happy with me right now.”

“I think I can help with that.” Slim cupped his hands around Red’s sides, letting his phalanges rest against the strained muscles of his conjured back.

At the first hint of pressure, a moan slipped from Red’s teeth. He tensed briefly, before practically melting. Having his ecto body summoned for months on end meant that he had to deal with cramps, aches, and soreness that he didn’t usually have to deal with, being a skeleton. The impromptu massage was wonderful, attacking his sore spots and willing them to relax, releasing a wave of pleasure-pain that sent shivers up his spine.

“oh fuck... yer the best,” he moaned. He could feel Slim’s magic begin to gather and heat up his bones, obviously affected by Red’s moans, but still dutifully working over his muscles.

Red leaned forward, slumping against Slim’s chest. The material of Slim’s tank top caught against Red’s nipples, and he groaned in actual pain, the swollen and sensitive nubs sending sharp shocks through him. They had been growing heavier and fuller as his due date came closer, and with the increased size came an ache that refused to leave him.

Before he could push back, though, the pain swelled. Much to his horror, a wave of liquid magic welled out of his nipples, staining Slim’s tank top with light red. They both froze, silence settling between them. Embarrassment made Red’s skull flush deeply, rapidly, and he stuttered, “u-um, i... yer shirt...”

Slim’s magic snapped into place, the bulge of his cock pressing against Red’s wet folds through their clothing and making him moan. Red’s sockets widened, and he leaned back, looking at his mate. Did he really just...?

“Well, well,” Slim purred, turning a smirk up towards Red. It was a dark one, full of promise and desire. “You’re leaking, darling.”

Red flushed impossibly deeper, wriggling in Slim’s lap. “shuddup! i can’t help it!” It was just his body getting ready to feed the little one, nothing else. “it’s just a little magic...”

Slim brought one hand around, and dragged one thumb across Red’s nipple, collecting the magic that beaded there. Pinning Red with burning eyelights, he lifted his thumb up and licked the magic off of it, practically purring.

“Such a wonderful snack you’ve made.” He chuckled at Red’s stunned silence. “It would be a shame to waste it...”

“what, what are you-?” Red’s voice trailed off into a moan when Slim slid down on the couch, and closed his mouth around one of Red’s swollen breasts. A familiar tongue looped around the flesh, and slowly began to massage, squeezing and rolling down to the peak of his nipple. A small stream of magic spilled onto the awaiting appendage, and was quickly ferried down Slim’s conjured throat.

Red’s first instinct was to shove his mate away and demand to know what the hell he was thinking. But while he was still sensitive, he couldn’t deny that the ache began to lessen, if only slightly. But Slim’s pleased moans vibrated against him, and amongst the tinges of pain, a certain sort of warm pleasure began to fill him, starting in his rib cage and traveling down to his cunt. He lifted his hands and cupped Slim’s skull, tracing circles against the bone and sighing in contentment.

Though each soft squeeze only pulled out a tiny amount of magic, by the time Slim sat back, the breast he had been working over felt so much lighter, less sore and full.

And he’d soaked his shorts with a big wet spot by his surprised arousal, which Slim looked stupidly smug about when he dropped a hand to trace his slit through his shorts. Red slapped a hand over his mouth before he could speak.

“just don’t, ya fucking perv. don’t even say it.” He shifted his hips uncomfortably.

“i’ll let you suck the other if you hurry up and fuck me,” Red grumbled after a moment. Slim smirked.

“Deal.”

**Author's Note:**

> ...this is not my kink at all lmao. Sorry if it’s short, I wasn’t into it.


End file.
